Aeroplane



C. F. JENKINS.

AEROPLANE.

APPLICATION FlLED JULY 9.1919.

Patented July 5, 1921.

3 SHEETS-SHEET 1.

I C. F. JENKINS.

AEROPLANE.

APPLICATION FILED .IULY 9,1919.

Patented July 5', 1921..

3 SHEETS-SHEET 3. r

6 Norm B UNITED STATES PATENT OFFICE.

CHARLES FRANCIS JENKINS, OF WA.SHINGTO1\I, DISTRICT OF COLUMBIA.

AEROPLANE.

Specification of Letters Patent.

Patented July 5, 1921.

Application filed July 9, 1919. Serial mi: 309,722.

in In aviation it is usual, in landing, to check the momentum of the machine by turning the machine upward thereby increasing the expenditure of machineadvancing energy upon the body' of air in front, but there are well known disadvantages in this method, which requires skill and quick action. The

I objects of this invention are to destroy the machines momentum quickly but without causing sudden deviation in the path of the machine, and at the same time to make special skill and quickness of far less importance. These ends are attained by arranging the upper main plane to have its upward inclination quickly increased without correspondingly changing the inclination of the lower main-plane, and at the same time automatically changing correspondingly the inclination of the horizontal rear elevating and depressing plane, whereby the lower main plane is aided in resisting sudden upward movement of the machine.

In the accompanyin drawings,

Figure 1 is a view s owing a machine embodylng my invention.

Fig. 2 is a front detail view. I Figs. 3 and 4 are detail views looking i tlzqhe direction of the arrows at 33, 44,

ig. 5 is a partial front view of a modified construction.

Figs. 6, 7 and 8 are enlarged detail views of devices of Fig. 5.

Figs. 9, 10 are details of lock and control devices.

Figs. 11, 12 illustrate a second modification.

In these figures, A re resents a common body of an aeroplane, B, the main planes and C the tail-vane, all normally having the of the links usual relative positions. Between the planes are forward struts D and rear struts D connected by diagonal tension wires E.

The angle made by the lower plane with the struts is, as usual, unchangeable, but the upper plane is pivoted at F to the upper end of the rear struts to swing in a vertical plane and its forward side is secured to the lpper G allowing it to be thrown up to a limited distance. The links G are virtually crank-like arms non-revolubly mounted upon a shaft H. rocking in bearings in the upper ends of the forward struts by links ends of the struts D, the shaft being in this instance shown as square and held in disks I revoluble in the struts D. Each link G normally extends downwardly and at its lower end is ivoted the lower end of one 8 the upper end of which is pivoted to the upper plane or the forward side of its framework. The link G is curved and the axis of its lower pivot normally lies, as seen in Fig. 1, a little to the rightof the axis of the shaft H so that it is locked, any upward strain exerted by the link tending to throw the arm or crank G against any suitable stop or stops J. Near the aviato have its upward inclination increased, the

pawl is retracted so that it can pass over that part of the arm on one side of the notch, but not far enough to pass over the part on the other side. The hand lever being now pushed forward, the pawl presses the longer portion of the arm L and carries it forward out of locking position when the upward pressure of the air upon the plane swings the plane upward aboutits rear pivots until the two links are extended as indicated in dotted lines in Fig. 1, the lever, if desired, still being held in the handwith its pawl retracted below the path of the shorter side of the arm L. As the link thus swings it pulls a wire O which rocks the horizontal tail vane so that it tends to lift this part of the machine andkeep the machine nearly level in fore and aft direction. Naturally, the greatly increased angle of the upper .plane gives much greater resistance'to advance and absorbs the momentum of the machine, and at the same time the normally inclined lower plane o'fi'ers great resistance to sudden rising of the forward end of the machine. The result is that speed of advance is greatly reduced, that the machine immediately begins to fall, and as it is kept level, the great wings act much like a large parachute as the machine gently descends to earth. When it comes fully to rest, gravity swings the front side of the upper plane to initial position, and if the pawl be retracted momentarily it reengages the arm L. Obviously, changes may be made while preserving thebroad invention. For example, the mounting and connections of the shaft H may be changed, or the arm .L may be extended to form a hand lever which ma be released, pushed over to swing the link (iout oflocked position, and then allowed to swing with the rocking shaft H. Some such modifications are shown in Figs. 5, 6, 7, 8, 9, 10, 11, 12, which also add some desirable features. In these figures 13, 14 represent upper and lower planes, and 15, 16 front and rear struts connected by common wire stays 17. The rear side of the upper plane is pivoted'at 18 to the upper end of the rear struts 16, while the front side of the same plane is connected to the front struts by motor-operated devices which allow the swinging of the plane by rapid yet gradual movement. A small motor 19, Fig. 5, is shown as carried by the upper plane, and, by usual worm gearing 20, rotating a drum 21' on a shaft 22.. Pulleys 23, 24 are fixed to each strut and to the upper plane just above the strut, and from the drum a cable 25, 113V! ing adjusting turn buckles 25, passes around each air of pulleys to form therewith a small block and tackle which, when the motor runs in the proper direction, draws the plane down upon the struts, or, when the motor runs in the opposite direction, allows the forward side of the plane to swing from its struts under the strong air pressure due to the machines advance. On some or all the struts 15 a perforated lug 26 extends upward, when the upper plane rests upon the strut, between coacting lugs 27, and a cotter pin 28 is passed through the three securely holding the plane down.

I These pins may be connected to the cable 25 (Fig. 9) in such way that slight rotation of the motor withdraws them. A closed liquidfilled cylinder 29, Fig. 10, may be secured to one or more of the struts and provided with a piston 30 carried by the plane above, a by-pass 31' extending from the upper part of the cylinder to the lower part so that the fluid may flow around the piston allowing movement in either direction. A valve '32 controls the by-pass and in effect locks the plane in any position. These locking and controlling devices are usable with all the forms herein set forth.

Instead of the drums and cables, I ma em 10y an extension 33 of the motor sha t (Flg. 11) and provide it at intervals with worms 34 to engage worm gears 35, each ly-.

ing between lugs 36 borne by the upper plane, and splined to a threaded vertical shaft 37 working in said lugs and, by oppositely inclined threads, in a nut fixed to the corresponding strut. Obviously rotation .of the motor carries the plane to and from the struts and holds it securely at any point where the motor may allow it to remain.

What I claim is:

1. The combination with a suitable aeroplane body, of a main supporting plane connected to the body extending equally on each side thereof andarranged to swing upwardly as a whole about an axis near its own rear side, a tail vane arranged to swin similarly in unison with the plane, an

means whereby an operator may prevent and permit such swinging.

2. A biplane having one of its supporting main planesfixed to the fuselage or body andthe other of its main supporting-planes pivoted near its rear side to swing upward as a whole through'a positively limited angle, combined with means normally locking the pivoted plane positively against swinging, and operator controlled devices for rendering the locking means ineffective.

3. The combination with a suitable aeroplane body and relatively fixed main plane, of a second main plane arranged to swing upwardly, as a whole, about an axis near its rear side to increase the surface resisting forward movement in the air, and means for automatically limiting the rate of the swinging permitted.

4. The combination with a biplane having its body, struts, tail vanes, and main supporting planes in usual relative positions struts, of a second main supporting plane hinged to the rear line of struts to swing upwardly, devices for locking the forwar side of the hinged plane to the forward line of struts; and o erator controlled devices for whatever the air pressure, means for releas- I rendering the ocking devices operative or ing the locking means, means for limiting 10 inoperative at will. to'a small angle the swinging of the released- 6. The A combination with an aeroplane plane, and means for automatically limiting 5 body of a main supporting plane arranged the rate of swinging movement.

for swinging upwardly under air pressure In testimony whereof I hereunto afiix my about \an axis near its rear side, means for signature.

locking the plane against such swinging I CHARLES FRANCIS JENKINS. 

